TI LDC1101 1.8 V inductance-to-digital converter

Texas Instruments (TI) has introduced the LDC1101 inductance-to-digital converter (LDC). The product is a 1.8 to 3.3 V, high-resolution data converter designed for short-range, high-speed, contactless sensing of position, rotation or motion. It provides accurate measurements in both controlled and harsh environments, making it suitable for automotive, consumer, industrial, computer and communications applications.

The converter features dual inductive measurement cores, allowing for 16-bit resonator resistance (R_P) and inductance (L) measurements at more than 150 ksps. Simultaneously, the converter can perform 24-bit resolution inductance measurements at more than 180 ksps. The product includes a threshold-compare function that can be dynamically updated while the device is running, simplifying designs such as high-speed gear counting.

The converter supports a wide range of inductor/capacitor (LC) combinations with oscillation frequencies ranging from 500 kHz to 10 MHz and R_P ranging from 1.25 to 90 kΩ. The device is configured and conversion results retrieved through a simple 4-wire SPI. The only external components necessary for operation are a 15 nF capacitor for internal LDO bypassing and supply bypassing for V_DD.